Vitamins A, C and E trials for osteoarthritis
Six of the eight trials in this review article investigated the potential beneficial role of vitamin E for osteoarthritis, while one studied the effectiveness of vitamin C and another looked at selenium ACE. The number of participants included in these trials ranged from 30–136 and the trial period ranged from 10 days to two years.
Two trials out of four demonstrated the effectiveness of vitamin E supplements in reducing pain and overall symptoms in osteoarthritis when compared to placebo treatment. The other two trials found they had no significant benefits.
Two RCTs out of two found no significant difference between participants who received vitamin E supplements or diclofenac with respect to pain reduction and overall improvement of most symptoms.
One trial of 133 people compared the treatment outcome of participants with osteoarthritis who were randomly selected to receive either 1 g vitamin C supplements or placebo tablets once a day for two weeks. Compared to the placebo group, participants on vitamin C reported a significant improvement in joint pain and physical function at the end of the trial.
Another study‡ compared the treatment outcome of 30 people with osteoarthritis who were randomised to receive either selenium ACE supplements or placebo tablets for six months. There was no significant difference in the level of pain reduction and the degree of general health improvement at the end of the trial period.
In this trial, 64 participants with osteoarthritis of the knee received either daily doses of 400 mg vitamin E (produced from palm oil) or 500 mg glucosamine sulphate three times a day for six months. Both groups improved but there were no differences between the groups in pain or function.
This trial looked at 102 people who received one of the following treatments a placebo over a three-month period:
- vitamin E
- conjugated linolenic acids (CLAs)
- a combination of vitamin E and CLAs.
The participants’ conditions as assessed by the physician, pain (morning, night, post-activity), morning stiffness, number of swollen and tender joints and disease activity improved in all groups except the placebo group. The greatest improvements were in those taking CLAs alone or in combination with vitamin E.
‡ A trial of low quality. Results of this trial were given a lower weighting when we came to our conclusion about the compound.